lauth



(Nu Mdel.)

J. N. LAUTH. Y FURNAB FOR METALLURGICAL PURPOSES.

Patented'oot. L1, 18492.

UNITED STATES PATENT OFFICE@ JOHN N. LAUTH, OF ST. LOUIS, MISSOURI, ASSIGNOR TO THE LAUTH PATENT FURNAOE COMPANY, OF SAME PLACE.

FURNACE FOR METALLURGICAL PURPOSES.

SPECIFICATION forming part of Letters Patent No. 484,328, dated October 11, 1892.

Application filed December 10,1891. Serial No. 414,647. (No model.)

To all whom i525 rnwy concer-71,:

Be it known that I, JOHN N. LAUTH, a citizen of the United States, and a resident of St. Louis, in the State of Missouri, have invented new and useful Improvements in Furnaces for Metallurgical Operations; and I do hereby declare the following to be a full, clear, and exact description of said invention, reference being had to the accompanying drawing,and to Io the letters of reference marked thereon, which form a part of this specification.

My invention relates to certain new and useful improvements in metallurgical furnaces for heating and puddling iron or steel.

The object of my invention is to provide a furnace which Will be effective in operation and at the same time heat the billets, piles, slabs, ingots, or bars to the desired temperature with the smallest amount of fuel, andto zo this end I construct the melting or heating hearth of the furnace inclined downward toward the stack, as is usual in this class of furnaces, and the roof of said furnace inclined upward from the front of the fire-chambertoward the neck or stack of the furnace, so that the products of combustion will strike against the wall above the outlet of the furnace and be reverberated or directed back onto the metal to be heated or melted on the hearth,

3o while at the same time the carbonio-acid gas, together with the slag, is. allowed to pass to the bottom of the stack. Heretofore in the construction of furnaces of this class it has been the prevailing method to provide a roof 3 5 or arch over the melting-chamber inclining downward to the stack end of the furnace, and by this construction of roof the drawing off of the products of combustion before the same are thoroughly united with air and de- 4o prived of their heat is practically the result accomplished, so that the percentage of heat actually utilized is but a small portion of that which goes up the stack. This is due, mainly, to the fact that the flame coming from the fire-chamber is so dense as to be only partially combusted by reason of not being permitted to be thoroughly intermixed with air, which, even though injected into the fire-chamber, is in a great measure carried alongin the dense 5o iiame without being` taken up or united before entering the stack. As the main essential to the perfect combustion of fuel is thorough intermingling of the oxygen of the air therewith, it has been my purpose to provide not only for the expansion of the fiame, where- 5 5 by it will take up a greater percentage of air, but for the coniining and retention of the Haine and its attendant gases within the melting-chamber, so that time, which is essential for this thorough mixing with the air, maybe 6o given and the gases combusted before entering the stack.

My invention consists in constructing a furnace for metallurgical operations with a firechamber, hearth, and interposed bridge-wall of usual or suitable construction and with a rear deIiecting-wall, an exit to the stack below the deflecting-wall, and a roof inclined upward from the front wall of the lire-chamber to the rear deflecting-wall, substantially as 7o hereinafter described, whereby the gases of combustion and partially-commingled air are carried freely over the bridge and through a combustion-chamber of constantly-increasing area to the rear of the furnace, and by contact with the rear deecting-Wallare returned and more thoroughly commingled and the inflammable gases consumed before passing to the stack.

In the accompanying drawing I have illus- 8o trated the invention as applied to a heatingfurnace for purposes of heating and Welding metal. In all respects other than the inclination of the roof A the furnace does not dier, essentially, from other well-known forms of this type, it' being usual to have the bridge B to partially divide the tire-chamber C from the melting-chamber D, and also to locate the neck E, forming the entrance into the stack F, at the sloping end of the hearth G. 9o

At the stack end of the furnace a wall His formed instead of -the usual arch, which, instead of clicking the flame and facilitating its withdrawal from the chamber D, presents a barrier for defiecting back the expended flame and gases, which are further combusted by meeting the heated Haine coming directly over the bridge-Wall from the fire-chamber. It is obvious that the Wall H may be concaved if found convenient, as illustrated by the dotted roo lines, as by that means the detiecting action of the same may be better accomplished.

By inclining they arch orfrooff,'asi shown and described, sothat theI flame vWill strike thev f f rear yWall and be flelectedy back onto the met al to be heated, a complete combustion is effected f and a saving; of at leasty twenty-fiveifper cent;v

yof the fuel. f The flame produced ybythe, re#

' verberatoryy actiony is a nonoxidizing hanne,y

kIO

ythus saving in the Waste ofkr metal from oney yhalf to three per cent.y over the old method of heating. i f f The action of the furnacebrieiiydescribed yis as follows: yThey air-blast iK, located under t the grate of the nre-chamber, ejeets air into the burning fuel to make the combustion asv rapid as possible, asis usualy Wherer this device is employed; but thev flamey which cornes over the bridge dividing the fire-chamber from ythe melting or heating chamber is of such density thamnehvof the Iair is carried along withoutbeingintimatelymixed. Byfthe gradf nally-increasingsze of the melting-chamber the iame isv allowed to increase its volume, f thereby n uiting with ytheair more com pletely,

y 1 and atthe samev timey being carried along to ythe stack end of the furnace, asiindicated by 1 the arrows ynearthe reofwhere it is deliected ibaok' bythe wall H. f The return gases, hav,- ing had more spaee for expansion andinore' i time formixingwiththe air,y are met by they vliamediremt :from thev {ire-chamber and oombusted. The carbonio-acid gaswhieh is gen-l v erated, rand which is necessarilya present elef vment,;is carried off first by virtue of itsdensity,

thnsfleavingthe ame and gases, which are vthe rearI of thefnrnace and.y by contactwith 6o 'thoronghlyiningled with the airand consumed before' passingvto the stack', as eq'xlained.y f f f deeoted back on the articles to'bemelted of a 35,

non-oxidizing nature. 'The action, therefore, f

k'nf theame andy gases is such as tey be Veryv ythoionghlyr utilized.y in the melting-chamber f f f before being taken u p the staclnft being un: f derstoodfthat the expansion of the'iiame andv 4o yg,asesf,fas Wellfas the ytimetheyam retained within the furnace, acts'to make them morer f readily teombnstibiel beforey they leave ythe melting-chamber.

Havingy thus deseribedmy invention, what 45 f f f rI claim, and' desire tor secure yby Letters Patf f A furnace for metallnrgieal operations'conf strueted, as herein described, with a fire-chamber,k a rhearth'for the metaha bridge-Wall in- 50 terposed betweenlthe fire-chamber andv the hearth,fa deiiectng-wall at the rear,y an kexit l f f to the stack below the rear defiecting-wall,y and a roof inclined upward from the'front Wall of,y the rfreehamber to the rear rdeiieeting-Wall,

freely over the bridge and through a eonnbusi-y f v y tion-chamber of: constantly-increasing area to the rear defiecting-wall are returned and ,morer yIn testimony whereof Iiafx my signature in l n,

presence'of two snbsoribingwitnesses.

i f vJOHN N. LAUTH.

Witnesses:

f WM.ANDR,=-y t VALENTINE 'Warmr f v v 55 'f whereby the gases of combustion 'are carried f f 

